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Fraunhofer developing fuel cell system to power the home

Fraunhofer developing fuel cell system to power the home
The cell stacks that are the heart of a home fuel cell system being developed by Fraunhofer (Photo: Fraunhofer IKTS)
The cell stacks that are the heart of a home fuel cell system being developed by Fraunhofer (Photo: Fraunhofer IKTS)
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The cell stacks that are the heart of a home fuel cell system being developed by Fraunhofer (Photo: Fraunhofer IKTS)
The cell stacks that are the heart of a home fuel cell system being developed by Fraunhofer (Photo: Fraunhofer IKTS)

As the world shifts to alternative forms of energy, ways to make homes less dependent on the grid continue to gather steam. Fuel cells, which are more efficient and have lower emissions than internal combustion engines seem like a logical candidate for taking up the slack, so the Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) in Dresden is partnering with the heater manufacturer Vaillant to develop a domestic fuel cell system that uses natural gas to produce both heating and electricity.

Fuel cells have been around since 1838, and have long seemed like the power source of tomorrow, but it wasn’t until the 1960s that the first commercial fuel cells appeared, when they were used to power spacecraft. Though they’ve seen some applications in the automotive industry in the 1990s and the Ene-Farm home fuel cell became the world's first commercialized fuel cell system targeted at household heating and electricity generation with its release in Japan in 2009, fuel cells have struggled to find widespread adoption.

Part of the reason is their complexity and another is that they tend to be very expensive due, in part, to the need for precious metals like platinum for catalysts. Because such catalysts are easily poisoned by impurities, fuel cells also have a reputation for poor reliability. The Fraunhofer approach was to come up with a fuel cell for the home that’s simple, and can be installed and maintained like a common household gas heater that runs on natural gas.

Like the Bloom Box and SOFC system developed at the Technical Research Centre of Finland (VTT), the Fraunhofer system is based on solid oxide fuel cell (SOFC) technology, which uses a ceramic electrolyte to produce electricity as oxygen combines with hydrogen. SOFC's work at a higher temperature than other fuel cell designs, such as those used in cars. Where proton exchange membrane fuel cells (PEMFCs) car fuel cells can only reach 80⁰ C (176⁰ F), SOFCs can reach up to 850⁰ C (1,562⁰ F). In other applications, such heat is a problem, but for home applications it can be turned to the homeowner’s advantage for keeping the home warm or heating water.

Since ceramics can withstand high temperatures, its suitable for a SOFC, and this higher temperature makes it simpler to design and cheaper to operate. It also avoids using platinum or other precious metals as a catalyst, which brings down the cost.

Like most fuel cells systems, the individual CD-like Fraunhofer cells are very low power, producing less than a volt, so they need to be organized into stacks. In practice, the fuel cell is hooked up to the domestic gas supply. As the gas enters, a reformer breaks up the gas into a hydrogen-rich mixture, which reacts with the stack in what is called “cold combustion” to produce heat and electricity. Meanwhile, there’s an afterburner to increase efficiency from the exhaust gases.

According to Fraunhofer, the current design is as compact as a gas heater, and can be installed in the same places as a heater. But instead of producing just heat, it also puts out one kilowatt of electricity as well, which is about enough for a family of four. The technology is currently undergoing trials involving 150 units in homes in Europe as part of the Callux practice test to see how well they function in a domestic environment.

Fraunhofer and Valiant are now working on decreasing the cost of the fuel cells and increasing their service life.

Source: Fraunhofer

In a nutshell, it could bring the cogeneration at the house level. Making electricity and heat at the same time instead of just heat may bring the efficiency of the fuel usage from around 30% to 80% !!!
I think that is really cool and very green. I think it would make for a greener future. It could be used to charge electric vehicles. Perhaps the water vapor exhaust could be condensed to liquid water, hence, reducing the water vapor as a 'green house gas'?
I wonder ... The Baxi CHP uses natural gas for water heating and waste heat to drive a very clever vibrating Stirling Engine that generates about 1kW of electric as well. I wonder which is the most efficient
Bruce H. Anderson
A temperature of 1,562F is pretty toasty. Since recommended water temps in the tank are around 125F, let's hope they can scale back the source heat a little.
Jonathan Cole
This will not get too far without the addition of batteries for storage. One kW of electricity is not enough to power a home unless the energy can be stored and accumulated. No one uses energy at exactly a 1 kW/hour rate.
The fact is we already have battery systems lithium titanate (LTO) that are 95% efficient and they are most economically filled with solar energy. That is if you include the true economic costs of all other forms of energy conversion such as capital cost, maintenance cost, cost to health, cost to the planetary natural infrastructure, etc. In addition, these batteries can go for 20,000 deep cycles, are environmentally benign, do not explode or burn even with catastrophic breakage.
Not going to be worthwhile until they an get it down to $1/kw. also they tend to die rather fast from contamination of many things.
What happened to the BloomBox? Haven't heard a word since they put out a bunch of them 2? yrs ago?. Are they still working?
Bruce: Intense heat just needs dilution for a low temp solution. The big deal here is not just this one piece but rather how this can be teamed up with things like the article about supercritical solar concentrator systems to generate electricity, or syngas, or process municipal sewage to then get to syngas which in turn is distributed to consumers to make heat & electricity in their homes & on demand. Each piece works with something else across the region and across the economy. And all of this should be build able without fossil fuels or more importantly without expensive and scarce materials.
It would be a lot cheaper to use and ICE to convert the gas into heat and electricity.
And the ICE can run on alternative fuels in an emergency.
Stephen N Russell
Mass produce for use worldwide. Retro fit for homes, condoes, hotels, resorts, colleges, hospitals alone. '
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